[Coco] Fwd: CoCo2 black and gray video only -- need help!

[Keith Monahan]

+list. FYI that removing the glue from the top of L1 variable inductor 
that is part of the RF Tank Circuit, and rotating it clockwise a bit 
brought color back.

More work needs done to sharpen/improve the video, so things aren't 
perfect yet, but we're heading in the right direction.


-------- Forwarded Message --------
Subject: 	Re: [Coco] CoCo2 black and gray video only -- need help!
Date: 	Mon, 25 Oct 2021 02:04:27 -0400
From: 	Keith Monahan <keith at techtravels.org>
To: 	Rocky Hill <qbancoffee at yahoo.com>



Rocky,

Thanks much for all those links. I have not seen the majority of them. 
Especially the RF modulator one. There's so much out there it's 
impossible to have seen them all!!

Turning the variable inductor clockwise about 1/4 turn did the trick! I 
had played with the other one, and the trim cap with no success. This 
one was covered in glue, and I wasn't even sure what it was, tbh.

So I've got color back, but the video looks pretty crappy. And is more 
blurry than the black and gray text.

Looks like that rgbtohdmi might do the trick, but like much these days 
is out of stock. Once I've had some sleep I'll need to research and go 
through the other links.

Made all the difference! Thanks for the post!

Keith


On October 25, 2021 12:42:48 AM Rocky Hill <qbancoffee at yahoo.com> wrote:

> I agree, I wouldn't mess with a CRT tv off of Ebay unless it was a 
> really good deal
> and it was local. I'd be more open to Craigslist if the tv is nearby 
> and in the free section.... maybe.
>
> You might have seen this already but I'll include it here just in case.
>
> AC of AC's 8 Bit Zone shows how he accidentally made his CoCo 2
> output color again by touching the board in the RF can.
> It's not a long video and it's worth a watch.
>
> The part I'm talking about is at around
> 7:30
>
> #SepTandy Coco-2 RF Modulator Fix <https://youtu.be/89zaEyWk4uA>
>
> 	
>
> 	
>
>
>     #SepTandy Coco-2 RF Modulator Fix
>
> <https://youtu.be/89zaEyWk4uA>
>
>
>
>
> If your're interested in HDMI out, there is a reasonably priced open
> source solution you've probably seen already called the RGB to
> HDMI adapter. It's been used in a bunch of retro systems(Amiga as 
> well) and if you're
> comfortable with surface mount components you can build one yourself.
>
> Once you have the adapter you'll need a raspberry pi zero.
>
> Here is a link to the project with all of the gerbers, instructions and
> firmware.
> GitHub - hoglet67/RGBtoHDMI: Bare-metal Raspberry Pi project that 
> provides pixel-perfect sampling of Retro Computer RGB/YUV video and 
> conversion to HDMI <https://github.com/hoglet67/RGBtoHDMI>
>
> 	
>
> 	
>
>
>     GitHub - hoglet67/RGBtoHDMI: Bare-metal Raspberry Pi project that
>     provid...
>
> Bare-metal Raspberry Pi project that provides pixel-perfect sampling 
> of Retro Computer RGB/YUV video and convers...
>
> <https://github.com/hoglet67/RGBtoHDMI>
>
>
>
> Aaron Newcomb of the retro hack shack is selling assembled units now.
> https://thesourceshow.org/ <https://thesourceshow.org/>
>
>
> I've assembled a few and even contributed some testing and feedback
> to make it more CoCo friendly. I have a video comparing the RF output on
> trash picked TV and on an HDMI monitor if you're interested.
>
> Testing Beta 37 of the RGB to HDMI code <https://youtu.be/uaO6_TCbIe8>
>
> 	
>
> 	
>
>
>     Testing Beta 37 of the RGB to HDMI code
>
> <https://youtu.be/uaO6_TCbIe8>
>
>
>
>
> I use the RGB to HDMI adapter often but I do get nostalgic for the RF out
> so I occasionally plug it back in to play some games.
>
> Good luck!
>